The Properties of the New Composite Antifriction Parts for Printing Equipment’s Friction Units

Tetiana Anatoliivna Roik,Yuliia Yuriivna Vitsiuk

doi:10.20535/2077-7264.2(56).2017.84485

Abstract

The paper summarizes the formation of new materials’ structure and properties after using a new hot isostatic-pressing technology. It shows the efficiency of the developed technology of production and the following heat treatment for the new high speed bearings, which is confirmed by the results of complex experimental and industrial tests. Such technology is able to ensure the high and stable level of the functional properties.The experimental results of the new composite bearing material’s properties in a comparison with the already known nickel composite have been presented. The article shows that the dense friction films were formed on the contact surfaces during tribological tests. All the friction surfaces are covered by the dense antiscoring films, the so-called as secondary structures. They consist of the chemical elements of bearing and counterface, and solid lubricant СаF2. During the friction process, the different chemical reactions took place between O2 of the air and elements of researched specimen and steel R18 counterface at high rotation speeds and loads. Such chemical processes result in formation of friction films, which protect contact pairs against intensive wear and stabilize a work of friction unit in printing machine.So, we have developed a new effective bearing materials, based on Ni alloy ЕP975–CaF2 system with high physical mechanical and tribotechnical properties performing well in more severe conditions than the already known sintered alloy. The new materials have an advantageous level of tribotechnical characteristics due to the tribofilms formed on the contact surfaces by dragging of calcium fluoride to cover the entire friction area.The full-scale industrial tests of ЕP975–CaF2 bearings showed increase in wear resistance by a factor up to 10 compared with the already known bearings in high speed printing machines’ friction units (in particular, Heidelberg Speedmaster SM-102-FPL and KBA Rapida-105) at a load up to 5 MPa and a rotation speed up to 6000 rpm.

Highlights

The questions of using friction materials takes a central place in the general problem with increasing machines’ and equipment quality
Such effects are peculiar to the friction units of printing machines, equipment of thermal and rolling shops, and energy equipment
Experimental results and discussion The structure was studied using a raster electron microscope; calcium fluoride in the matrix was identified by using a scanning electron microscopy (SEM)

Summary

Introduction

The questions of using friction materials takes a central place in the general problem with increasing machines’ and equipment quality. First of all, it concerns the bearing materials for friction joints, which are falling under the influence of different kinds of contact interaction. The heaviest operating conditions are high loading (3.0–7.0 MPa), with the temperature 500–600° C or high speeds of rotation up to 10000 rpm [2,3,4] Such effects are peculiar to the friction units of printing machines (high speed revolution machines), equipment of thermal and rolling shops, and energy equipment. The performance of the increased loads, high speeds of the rotation, influence of the oxidizing environment built a list of aggressive factors, which cause the intensive wear rate of the friction units in printing equipment [1,2,3,4,5]

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Results

Conclusion